Matt Kuchar beat Hunter Mahan 2&1 in the final of the WGC-Accenture Matchplay Championship at Dove Mountain in Arizona to win the first World Golf Championship of the season.
In the consolation match, Australian Jason Day beat English Ryder Cup legend Ian Poulter 1up to finish in third place.
Many people fancied defending champion Mahan - a man who hadn't been down in any of his previous matches - but Kuchar made a fast start and moved 4up after eight holes.
Mahan won the 10th and the 11th, but a Kuchar birdie at the par-5 13th restored his three hole advantage.
Mahan fought back to win the 14th and 16th holes, but was forced to concede the 17th and hand Kuchar the title.
In the consolation match, Day won the 14th to open up a three hole lead and - despite a characteristic Poulter fightback on 16 and 17 - managed to hold on for the win.
Poulter had earlier been defeated 4&3 by Mahan, while Kuchar disposed of Day by the same winning margin.
It was a long weekend for the players, with 36 holes played on Saturday and Sunday after snow postponed the first round.
The delay didn't affect Kuchar and Mahan, but world number one and two Rory McIlroy and Tiger Woods were knocked out in round one, along with Keegan Bradley, Adam Scott, Lee Westwood and Charl Schwartzel.
Kuchar beat Sergio Garcia in the second round and Nicolas Colsaerts in the third before a 3&2 triumph over surprise package Robert Garrigus in the quarter final.
Mahan, meanwhile, progressed serenely through the stages, beating Richard Sterne and Martin Kaymer comprehensively before a hard-fought 1up victory over US Open champion Webb Simpson.
"I'm not sure I can explain how excited I am to have won this tournament," Kuchar said.
"To come out on top after six matches of playing the top 64 guys in the world is an incredible feeling."
WGC-Accenture Matchplay Championship The Golf Club at Dove Mountain, Marana, Arizona Feb 20-23, purse $8,750,000, par 72
1) Matt Kuchar - $1,500,000 2) Hunter Mahan - $875,000 3) Jason Day - $615,000 4) Ian Poulter - $500,000 T5) Graeme McDowell - $275,000 T5) Webb Simpson - $275,000 T5) Steve Stricker - $275,000 T5) Robert Garrigus - $275,000
Bold signified Titleist golf ball use
